共查询到20条相似文献,搜索用时 15 毫秒
1.
Understanding security failures of cryptographic protocols is the key to both patching existing protocols and designing future schemes. The design of secure remote user authentication schemes based on elliptic curve crypto-graphy (ECC) for mobile applications is still quite a challenging problem, though many schemes have been published lately. In this paper, we analyze an efficient ID-based scheme for mobile client–server environment without the MapToPoint function introduced by He et al. in 2012. This proposal attempts to overcome many of the well known security and efficiency shortcomings of previous schemes, and it also carries a claimed proof of security in the random oracle model. However, notwithstanding its formal security arguments, we show that He et al.’s protocol even cannot attain the basic goal of mutual authentication by demonstrating its vulnerabilities to reflection attack and parallel session attack. Besides these two security vulnerabilities, their scheme also suffers from some practical pitfalls such as user anonymity violation and clock synchronization problem. In addition, we carry out an investigation into their security proof and propose some changes to the scheme so that it can achieve at least its basic security goal, in the hope that similar mistakes are no longer made in the future. 相似文献
2.
Session Initiation Protocol (SIP) has been widely used in the current Internet protocols such as Hyper Text Transport Protocol (HTTP) and Simple Mail Transport Protocol (SMTP). However, the original SIP authentication scheme was insecure and many researchers tried to propose schemes to overcome the flaws. In the year 2011, Arshad et al. proposed a SIP authentication protocol using elliptic curve cryptography (ECC), but their scheme suffered from off-line password guessing attack along with password change pitfalls. To conquer the mentioned weakness, we proposed an ECC-based authentication scheme for SIP. Our scheme only needs to compute four elliptic curve scale multiplications and two hash-to-point operations, and maintains high efficiency. The analysis of security of the ECC-based protocol shows that our scheme is suitable for the applications with higher security requirement. 相似文献
3.
《Journal of Microcomputer Applications》1989,12(3):213-232
DIAS is a multilevel-multiprocessor picture information system architecture. It receives many pictures simultaneously from its environment and ‘decides’ how to process them according to its built up experience.This paper deals with the hardware design of the image preprocessor for the DIAS system. Several details concerning the image acquisition are discussed, including a unique photoarray camera and a hardware preprocessor which act to acquire and reduce the amount of data provided to the Master-Planner processor of the DIAS structure. In particular, the image preprocessor receives the image data in parallel and generates a number of critical image parameters, such as average intensities of various picture regions, geographic locations of the informative picture regions, number of pixels, etc., appropriate for fast decision making by the Master-Planner processor. The internal circuitry and functions of the image preprocessor are presented as well as a simple VLSI realization. 相似文献
4.
Mobile pay-TV systems represent an application of important electronic commerce, providing mobile users with the multimedia services. In 2016, Farash and Attari employed the elliptic curves and bilinear pairing technologies to design a one-to-many authentication scheme for mobile pay-TV systems. They claimed that their scheme provides a high level of efficiency and can resist most attacks on mobile pay-TV systems. In this paper, we point out their scheme cannot achieve the fundamental requirement of authentication that is, the mutual authentication. In addition, their scheme still suffers from three security weaknesses. 相似文献
5.
A digital authentication watermarking scheme for JPEG images with superior localization and security 总被引:1,自引:0,他引:1
The drawbacks of the current authentication watermarking schemes for JPEG images, which are inferior localization and the
security flaws, are firstly analyzed in this paper. Then, two counterferiting attacks are conducted on them. To overcome these
drawbacks, a new digital authentication watermarking scheme for JPEG images with superior localization and security is proposed.
Moreover, the probabilities of tamper detection and false detection are deduced under region tampering and collage attack
separately. For each image block, the proposed scheme keeps four middle frequency points fixed to embed the watermark, and
utilizes the rest of the DCT coefficients to generate 4 bits of watermark information. During the embedding process, each
watermark bit is embedded in another image block that is selected by its corresponding secret key. Since four blocks are randomly
selected for the watermark embedding of each block, the non-deterministic dependence among the image blocks is established
so as to resist collage attack completely. At the receiver, according to judging of the extracted 4 bits of watermark information
and the corresponding 9-neighbourhood system, the proposed scheme could discriminate whether the image block is tampered or
not. Owing to the diminishing of false detection and the holding of tamper detection, we improve the accuracy of localization
in the authentication process. Theoretic analysis and simulation results have proved that the proposed algorithm not only
has superior localization, but also enhances the systematic security obviously.
Supported by the National Natural Science Foundation of China (Grant No. 60572027), the Program for New Century Excellent
Talents in University of China (Grant No. NCET-05-0794), the Sichuan Youth Science & Technology Foundation (Grant No. 03ZQ026-033),
the National Defense Pre-research Foundation of China (Grant No. 51430804QT2201) and the Application Basic Foundation of Sichuan
Province, China (Grant No. 2006 J13-10) 相似文献
6.
Frederico Durao Karunakar Bayyapu Guandong Xu Peter Dolog Ricardo Lage 《Multimedia Tools and Applications》2014,71(2):905-929
Medical information is a natural human demand. Existing search engines on the Web often are unable to handle medical search well because they do not consider its special requirements. Often a medical information searcher is uncertain about his exact questions and unfamiliar with medical terminology. Under-specified queries often lead to undesirable search results that do not contain the information needed. To overcome the limitations of under-specified queries, we utilize tags to enhance information retrieval capabilities by expanding users’ original queries with context-relevant information. We compute a set of significant tag neighbor candidates based on the neighbor frequency and weight, and utilize the qualified tag neighbors to expand an entry query. The proposed approach is evaluated by using MedWorm medical article collection and results show considerable precision improvements over state-of-the-art approaches. 相似文献
7.
Design and implementation of a workflow-based resource broker with information system on computational grids 总被引:1,自引:0,他引:1
The grid is a promising infrastructure that can allow scientists and engineers to access resources among geographically distributed
environments. Grid computing is a new technology which focuses on aggregating resources (e.g., processor cycles, disk storage,
and contents) from a large-scale computing platform. Making grid computing a reality requires a resource broker to manage
and monitor available resources. This paper presents a workflow-based resource broker whose main functions are matching available
resources with user requests and considering network information statuses during matchmaking in computational grids. The resource
broker provides a graphic user interface for accessing available and the appropriate resources via user credentials. This
broker uses the Ganglia and NWS tools to monitor resource status and network-related information, respectively. Then we propose
a history-based execution time estimation model to predict the execution time of parallel applications, according to previous
execution results. The experimental results show that our model can accurately predict the execution time of embarrassingly
parallel applications. We also report on using the Globus Toolkit to construct a grid platform called the TIGER project that
integrates resources distributed across five universities in Taichung city, Taiwan, where the resource broker was developed.
相似文献
Po-Chi ShihEmail: |
8.
Recently, Sun et al. (Quantum Inf Process:14:2125-2133, 2015) proposed a quantum private comparison protocol allowing two participants to compare the equality of their secrets via a malicious third party (TP). They designed an interesting trap comparison method to prevent the TP from knowing the final comparison result. However, this study shows that the malicious TP can use the statistics attack to reveal the comparison result. A simple modification is hence proposed to solve this problem. 相似文献
9.
Hybrid electric buses have been a promising technology to dramatically lower fuel consumption and carbon dioxide (CO2) emission, while energy management strategy (EMS) is a critical technology to the improvements in fuel economy for hybrid electric vehicles (HEVs). In this paper, a suboptimal EMS is developed for the real-time control of a series–parallel hybrid electric bus. It is then investigated and verified in a hardware-in-the-loop (HIL) simulation system constructed on PT-LABCAR, a commercial real-time simulator. First, an optimal EMS is obtained via iterative dynamic programming (IDP) by defining a cost function over a specific drive cycle to minimize fuel consumption, as well as to achieve zero battery state-of-charge (SOC) change and to avoid frequent clutch operation. The IDP method can lower the computational burden and improve the accuracy. Second, the suboptimal EMS for real-time control is developed by constructing an Elman neural network (NN) based on the aforementioned optimal EMS, so the real-time suboptimal EMS can be used in the vehicle control unit (VCU) of the hybrid bus. The real VCU is investigated and verified utilizing a HIL simulator in a virtual forward-facing HEV environment consisting of vehicle, driver and driving environment. The simulation results demonstrate that the proposed real-time suboptimal EMS by the neural network can coordinate the overall hybrid powertrain of the hybrid bus to optimize fuel economy over different drive cycles, and the given drive cycles can be tracked while sustaining the battery SOC level. 相似文献
10.
11.
《Information and Software Technology》2013,55(6):1004-1016
ContextThe number of students enrolled in universities at standard and on-line programming courses is rapidly increasing. This calls for automated evaluation of students assignments.ObjectiveWe aim to develop methods and tools for objective and reliable automated grading that can also provide substantial and comprehensible feedback. Our approach targets introductory programming courses, which have a number of specific features and goals. The benefits are twofold: reducing the workload for teachers, and providing helpful feedback to students in the process of learning.MethodFor sophisticated automated evaluation of students’ programs, our grading framework combines results of three approaches (i) testing, (ii) software verification, and (iii) control flow graph similarity measurement. We present our tools for software verification and control flow graph similarity measurement, which are publicly available and open source. The tools are based on an intermediate code representation, so they could be applied to a number of programming languages.ResultsEmpirical evaluation of the proposed grading framework is performed on a corpus of programs written by university students in programming language C within an introductory programming course. Results of the evaluation show that the synergy of proposed approaches improves the quality and precision of automated grading and that automatically generated grades are highly correlated with instructor-assigned grades. Also, the results show that our approach can be trained to adapt to teacher’s grading style.ConclusionsIn this paper we integrate several techniques for evaluation of student’s assignments. The obtained results suggest that the presented tools can find real-world applications in automated grading. 相似文献
12.
LEE Hyeon-deok SON Myeong-jo OH Min-jae LEE Hyung-woo KIM Tae-wan 《中国科学:信息科学(英文版)》2012,(5):1019-1031
In early 2000,large domestic shipyards introduced shipbuilding 3D computer-aided design (CAD) to the hull production design process to define manufacturing and assembly information.The production design process accounts for most of the man-hours (M/H) of the entire design process and is closely connected to yard production because designs must take into account the production schedule of the shipyard,the current state of the dock needed to mount the ship’s block,and supply information.Therefore,many shipyards are investigating the complete automation of the production design process to reduce the M/H for designers.However,these problems are still currently unresolved,and a clear direction is needed for research on the automatic design base of manufacturing rules,batches reflecting changed building specifications,batch updates of boundary information for hull members,and management of the hull model change history to automate the production design process.In this study,a process was developed to aid production design engineers in designing a new ship’s hull block model from that of a similar ship previously built,based on AVEVA Marine.An automation system that uses the similar ship’s hull block model is proposed to reduce M/H and human errors by the production design engineer.First,scheme files holding important information were constructed in a database to automatically update hull block model modifications.Second,for batch updates,the database’s table,including building specifications and the referential integrity of a relational database were compared.In particular,this study focused on reflecting the frequent modification of building specifications and regeneration of boundary information of the adjacent panel due to changes in a specific panel.Third,the rollback function is proposed in which the database (DB) is used to return to the previously designed panels. 相似文献
13.
14.
In this paper, the Euler-Lagrange conditions for the extremization of a performance functional for a discrete time linear system with delay fire derived and this is then used for the estimation of states for the same system. The estimation problem is represented as a Two Point Boundary Value (TPBV) problem which is then solved numerically by using the steepest descent technique. 相似文献
15.
《Advanced Robotics》2013,27(3):249-272
A remote controlled robot for collecting information in disasters, e.g. earthquakes, is one of most effective applications of robots, because it is very dangerous for human beings to locate survivors in collapsed buildings and, in addition, small robots can move into narrow spaces to find survivors. However, previous rescue systems that use robots have a significant problem — a shortage of operators. In catastrophic disasters, in order to save victims, we must explore wide areas within a limited time. Thus, many rescue robots should be employed simultaneously. However, human interfaces of previous rescue robots were complicated, so that well-trained professional operators were needed to operate the robots and, thus, to use many rescue robots, many professional operators were required. However, in such catastrophic disasters it is difficult to get many professional operators together within a short time. In this paper we address the problem and propose a concept of rescue team organization in which professional rescue staff and volunteer staff work together for handling a catastrophic disaster. We point out the necessity for rescue robots which can be operated easily by non-professional volunteer staff. To realize a rescue robot which can be operated easily, we propose a rescue robot system which has a human interface seen in typical, everyday vehicles and a snake-like robot which has mechanical intelligence. We have demonstrated the validity and the effectiveness of the proposed concept by developing a prototype system. 相似文献
16.
《Information and Software Technology》2003,45(4):217-227
As multimedia information systems begin to infiltrate organizations, there arises a need to capture and disseminate knowledge about how to develop them. Little is thus far known about the realities of multimedia systems development practice, or about how the development of multimedia systems compares to that of ‘traditional’ information systems. Herein are discussed the findings of a survey of multimedia developers in Ireland. Practitioners generally agree that systematic approaches are desirable in order to beneficially add structure to development processes, but they are predominantly using their own in-house methods rather than those prescribed in the literature. 相似文献
17.
18.
Can we do without GUIs? Gesture and speech interaction with a patient information system 总被引:2,自引:1,他引:1
We have developed a gesture input system that provides a common interaction technique across mobile, wearable and ubiquitous computing devices of diverse form factors. In this paper, we combine our gestural input technique with speech output and test whether or not the absence of a visual display impairs usability in this kind of multimodal interaction. This is of particular relevance to mobile, wearable and ubiquitous systems where visual displays may be restricted or unavailable. We conducted the evaluation using a prototype for a system combining gesture input and speech output to provide information to patients in a hospital Accident and Emergency Department. A group of participants was instructed to access various services using gestural inputs. The services were delivered by automated speech output. Throughout their tasks, these participants could see a visual display on which a GUI presented the available services and their corresponding gestures. Another group of participants performed the same tasks but without this visual display. It was predicted that the participants without the visual display would make more incorrect gestures and take longer to perform correct gestures than the participants with the visual display. We found no significant difference in the number of incorrect gestures made. We also found that participants with the visual display took longer than participants without it. It was suggested that for a small set of semantically distinct services with memorable and distinct gestures, the absence of a GUI visual display does not impair the usability of a system with gesture input and speech output. 相似文献
19.
JUHANI HIRVONEN 《International journal of control》2013,86(5):1039-1043
The paper considers the Kalman-Bucy filter for a linear system when the measurement noise covariance matrix is singular. It is shown that the problem of infimizing the square of a linear functional of the state estimation error is the dual of the optimal singular linear regulator problem. Furthermore there is an optimal reduced-order Kalman-Bucy filter for minimization of the trace of the state error covariance matrix, when all extremal controls for a dual regulator have finite order of singularity, and no Luenberger observer is needed. The proof is constructive. Necessary and sufficient conditions for the existence of a reduced-order optimal estimator are derived. 相似文献
20.
This paper presents a framework for allocating radio resources to the Access Points (APs) introducing an Access Point Controller
(APC). Radio resources can be either time slots or subchannels. The APC assigns subchannels to the APs using a dynamic subchannel
allocation scheme. The developed framework evaluates the dynamic subchannel allocation scheme for a downlink multicellular
Orthogonal Frequency Division Multiple Access (OFDMA) system. In the considered system, each AP and the associated Mobile
Terminals (MTs) are not operating on a frequency channel with fixed bandwidth, rather the channel bandwidth for each AP is
dynamically adapted according to the traffic load. The subchannels assignment procedure is based on quality estimations due
to the interference measurements and the current traffic load. The traffic load estimation is realized with the measurement
of the utilization of the assigned radio resources. The reuse partitioning for the radio resources is done by estimating mutual
Signal to Interference Ratio (SIR) of the APs. The developed dynamic subchannel allocation ensures Quality of Service (QoS),
better traffic adaptability, and higher spectrum efficiency with less computational complexity.
相似文献
Chanchal Kumar Roy (Corresponding author)Email: |